Behind the scenes
The policeman can also be seen when Marty first walks into Courthouse Square in 1955. In footage deleted from the finished film, but reinstated for George Gipe's novelization, Doc hands the officer a bribe.
Can you bribe cops?
As well as this, section 347 of the code prohibits the acceptance of a bribe by any public official, explicitly listing police officers.
Who is Doc Brown's famous relative in back to the future?
The Brown family consisted of Dr. Emmett Brown, his wife Clara, and their two sons Jules and Verne named for Jules Verne. They were all involved in Doc's travels through time on their time traveling train.